[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference varese::basestar_open

Title:BASEstar Open Multiplatform Application Framework
Notice:Kit pointers: see topic 3
Moderator:VARESE::CORBETTA
Created:Tue Oct 02 1990
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:607
Total number of notes:1971

597.0. "Communication between B* Open Server and Client" by VAXRIO::MARCIUS () Fri May 02 1997 19:45

    Hi,
    	Here in Rio there many customers interested in B* Open.
    	But they are afraid of network perfomance.
    	When we create B* Open objects, these objects are stored in the B*
    Open Server(s) Node(s), aren't they ? I mean, the object is stored in
    the node where the concerning activity is running (one node from
    the node_list specified).
    	In B* Open Client nodes, there isn't any B* Open objects database to
    store the objects in a dual configuration, is it ? So, what the B* Open
    Client must to do is, whenever he wants to update/inquiry a B* Open
    data_point, it sends a put_value/get_value message to the B* Open
    Server. Is this correct ?
    	Then, suppose we have 3000 analog data_points, changing their
    value all the time. Will the B* Open Client send messages to the B*
    Open Server for each change in these analog points ? If will, the
    network perfomance won't be damaged ?
    	Where can i get information about the communication between B* Open
    Clients and Servers ? And about the projects that have already been
    done with B* Open: how many data_points they used ? There are some
    limitation in this number for a unique realm ? And about several realms
    running at the same time ?
    	Sorry for too many questions, but any help would be appreciated.
    	Regards,
    	Marcius Machado
    
T.RTitleUserPersonal
Name
DateLines
597.1Some answersVARESE::ZOCCOLADeprimitElatosLevatAlexandriaStratosMon May 05 1997 11:0564

##    	When we create B* Open objects, these objects are stored in the B*
##    Open Server(s) Node(s), aren't they ? I mean, the object is stored in
##    the node where the concerning activity is running (one node from
##    the node_list specified).

Correct.


##    	In B* Open Client nodes, there isn't any B* Open objects database to
##    store the objects in a dual configuration, is it ?

Sorry, but what do you mean by "dual configuration" ?
Do you mean a sort of "cache" kept in B* Client nodes ?


##	So, what the B* Open
##    Client must to do is, whenever he wants to update/inquiry a B* Open
##    data_point, it sends a put_value/get_value message to the B* Open
##    Server. Is this correct ?

Correct.


##    	Then, suppose we have 3000 analog data_points, changing their
##    value all the time. Will the B* Open Client send messages to the B*
##    Open Server for each change in these analog points ? If will, the
##    network perfomance won't be damaged ?

Here are some considerations.

First of all, B* allows the creation of structured data_points, that's to say
you can create arrays and structures in a way very close to the C language.

So,suppose you collect the 3000 data_point in an array or a struct, with a 
single get/put value you can transfer all of them (you say they change their 
value all the time, so it may have sense); then, you can use the Mapped Data 
Points feature to access them individually.

Second, if the data that are changing are on the Server side, you can use the
Trigger/Event/Event Parameters features to receive on the Client side only the
points that have changed their values.


##    	Where can i get information about the communication between B* Open
##    Clients and Servers ?

Just think of it like an RPC between the Clients and the Servers; then add a B* 
way of configuring where on the net to find the Realms you need.


## And about several realms running at the same time ?

There is no problem when several processes accessing diverse Realms on diverse
nodes on the net; the only limitation is that a single process cannot access
more than one Realm at the same time, but we will drop this limitation in one of 
the next releases.





		< Aldo >
597.2B* Open Client cache data area ?VAXRIO::MARCIUSWed May 07 1997 18:009
    
    	Sorry.
    	When i say dual configuration i want to mean B* Open Client nodes
    store data_points contents locally, in a cache data area. So there
    would be two areas with the same information stored.
    	Thanks for your help.
    	Regards,
    	Marcius Machado
    
597.3Not availableVARESE::ZOCCOLADeprimitElatosLevatAlexandriaStratosThu May 08 1997 10:305
There is no cache data area inside the client.


		< Aldo >